Woodland engineers providesoffers seatless and glandless piston valves. These piston valves that are available up to 4" size and do not have any stuffing box.Various advantageous features of piston valves are as follows: when any leakage is observed from the hole of the bonnet, specially provided for this purpose, it can be stopped on the line. The valves find best application in control of steam and thermic fluid line. They also have numerous applications in the control of liquids and gases. The piston valves are available in nd/16 and nd/25 rating.Following are some constructional features which include: the piston slides between the two packing rings made of asbestos ptfe and do not rotate, hence there is minimum ware. Two packing rings are separated by a ported lantern bush. The bottom ring rests on a cast machined grooved of the body and upper packing ring is being held and remained pressed by a bonnet on the top. The bonnet rests on the top ring, when tightened evenly by the nut of the stud presses the lantern bush which in turn presses the bottom ring. Advantage of the valves is when any leakage is observed from the hole of the bonnet, specially provided for this purpose, it can be stopped on the line. The valves find best application in control of steam and thermic fluid line. They also have numerous applications in the control of liquids and gases. The piston valves are available in nd/16 and nd/25 rating.
